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Promising Leuce poplar clones in sandy ridges between the rivers Danube and Tisza in Hungary: a case study
111-113Views:214An intensive integrated research and development work has been carried out on the improvement of Leuce poplars including primarily the native white poplar (Populus alba L.) and its natural hybrid grey poplar (Populus × canescens). More than 70 percent of the Leuce poplar stands can be found on calcareous sandy sites in the Danube–Tisza region, so they play a significant role in the poplar management of this part of the country. The most important task ahead of Hungarian poplar growers is to improve the quality of poplar stands and plantations based on selecting new clones and cultivars. The growth and yield of four promising Leuce poplar clones was evaluated on a marginal site in central Hungary. The clones ‘H 425-4’ (Populus alba L. × Populus alba L.), and ‘H 758’ (Populus alba L. Mosonmagyaróvár 124) seem to be suitable for wood production, while the ‘H 427-3’ (Populus alba L. × Populus alba L. cv. Bolleana) and ‘H 422-9’ (Populus alba L. × Populus grandidentata (Michx)) clones (with decorative stem form) could be better used for tree lines and ornamental plantations.
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DHAC-induced transgene overexpression in 35S-gshI GMO poplar (Populus × canescens)
78-83Views:33Relative gene expression levels of transgene gshI (γ-glutamylcysteine synthetase cloned from E. coli) were analyzed by qRT-PCR in two transgenic poplar (Populus × canescens) clones (11ggs and 6lgl) and wild type (WT). An extremely high expression level of transgene gshI was observed in the 6lgl clone (13.5-fold) compared to 11ggs (1.0) samples, which level was doubled (1.8-fold) in the DHAC (5.6-dihydro-5'-azacytidine hydrochloride) treated (at 10-4 M for 7 days) 6lgl samples but not in the 11ggs clone (0.4-fold). Contrary to this result, relative copy number of transgene gshI in the 6lgl clone was found to be less 60% less (1.0) then in the 11ggs samples (1.6). Relative expression levels of proper poplar gene gsh1-poplar showed significantly higher responsiveness to DHAC treatment than transgene gshI with the highest expression level in the untransformed (WT) poplar
clone (19.7-fold) compared to transformed 6lgl (8.7-fold) and 11ggs (2.5-fold) clones. For internal controls constitutively expressed housekeeping genes a-tubulin were applied. For data analysis, the 2−ΔΔCt method was used. DHAC applied in long-term cultures (27 days) at low concentrations (10-8 – 10-6 M) showed morphogenetic activity by initiating de novo root development of leaf discs. -
Examination of the decomposition of willow (Salix sp.), poplar (Populus sp.), reed (Phragmites australis) and mixed leaf litter with litterbag technique
111-115Views:77Leaf litter decomposition is one of the main ecological material cycle processes in waterfront areas. In this microcosm experiment, the rate of decomposition of the most frequently occurring dominant waterside plants were examined in the summer months of 2022 in a class “A” evaporation pan, using litterbag technique. The study provides information about the decomposition dynamics of willow (Salix sp.), poplar (Populus sp.), reed (Phragmites australis) and different leaf litter mixture combinations. Dry mass, exponential decay coefficient and the chemical parameters of the water (pH, conductivity, NH4+, PO43-, SO42-) were determined during the 84 days long experimental period. The weight loss curves showed negative exponential pattern in every case. On average, the different samples lost ~ 57% of their initial dry mass during the experimental period. The largest mass loss was measured in case of poplar (67.2%), while reed leaves had the smallest mass loss (47.25%). Based on the results, it cannot be proven, that mixed leaf litter accelerates the rate of decomposition.
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Microsatellite Diversity of Androgenic Black Poplar (Populus nigra)
60-67Views:70Genetic variation of somatic clones (1 to 35) of black poplar (Populus nigra) developed from two anther-donor trees N-SL and N-309 was determined by five SSR primer pairs. Twenty SSR alleles were detected, the number of alleles per marker ranged from 1 to 6, with an average of 3.3 including WPMS-2 (5 alleles), WPMS-4 (6 alleles), WPMS-6 (2 alleles), WPMS-20 (6 alleles) and PTR-4 (1 allele) detected by ALF (automatic laser fluorometer). A
dendrogram produced by SPSS11 based on the presence versus absence of SSR alleles discriminated the groups of somatic clones of N-SL from somatic clones of N-309. The polymorphic markers of WPMS-2 (5 alleles), WPMS-4 (6 alleles) and WPMS-20 (6 alleles) revealed clonal variation in 1 clone (37) out of the 6 from the N-309 tree, and three subgroups out of the 29 somatic clones from the N-SL tree (17 and 24), (2 and 14) and (10 and 15). The remaining 23 of the 29 N-SL somatic clones with uniform genetic similarity suggests a good degree of genetic stability in black poplar. Nevertheless, the new SSR-clones may provide useful new genetic resources for poplar breeding. -
Micropropagation of Leuce-poplar clones and its role in selection breeding
43-48Views:148Leuce-poplars (mostly white poplar and its natural hybrid grey poplar) are native tree species trough Hungary. They are covering more than 4.0 per cent of the Hungarian forested area (77 000 ha). The white (grey) poplars play a significant role in the forestation under sandy soil site conditions as well as they are of importance from nature conservation point of view as well.Long-term selection breeding work is going on at the National Agricultural Research and Innovation Centre Forest Research Institute (NARIC FRI), involving selection of fast-growing Leuce-poplar clones under dry site conditions.Micropropagation technology is relatively quickly spreading in forestry. In vitro multiplication of trees is applied mainly in fruit growing in Hungary, in case of forestry it is used mainly for selection breeding.This paper presents a short overview on the micropropagation trials with different Leuce-poplar clones and the early evaluation of the seedlings growing of the micropropagated clones/varieties. -
A simplified growing model for mixed black locust (Robinia pseudoacacia L.) and poplar (Populus spp.) plantations in the Danube-Tisza Interfluve
97-100Views:102This study presents a static model of mixed black locust (Robinia pseudoacacia L.) plantation stand structures for inventory stand structures between 10 and 40 years of age. Due to its local character, the model can be advantageous in planning tending operations, making structural factor predictions for the standing stock (main stand) after tending cuts, and preparing local wood production and silvicultural models. The model data presented in this paper show that poplars account for 55–62 % of the volume per hectare due to their faster growth rate in mixed black locust and poplar plantations. Maintaining the black locust part of the stand necessitates harvesting the poplars by the age of 10 at the latest.